在我的xcode项目中，用户手动绘制对象。例如，他们可以画一个苹果或三角形。
我需要保存我猜他们绘制的坐标或直线路径。
如何存储线路径或重新创建用户绘制的图像。 我不想保存图片，但我想通过了解具体的线路来了解用户绘制的图片？
这是代码
·H
int mouseMoved;
BOOL mouseSwiped;
CGPoint lastPoint;
UIImageView *drawImage;
viewdidload {
drawImage = [[UIImageView alloc] initWithImage:nil];
drawImage.frame = self.view.frame;
[self.view addSubview:drawImage];
self.view.backgroundColor = [UIColor lightGrayColor];
mouseMoved = 0;
}
.m
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
BOOL mouseSwiped = NO;
UITouch *touch = [touches anyObject];
if ([touch tapCount] == 2) {
drawImage.image = nil;
return;
}
lastPoint = [touch locationInView:self.view];
lastPoint.y -= 20;
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
mouseSwiped = YES;
UITouch *touch = [touches anyObject];
CGPoint currentPoint = [touch locationInView:self.view];
currentPoint.y -= 20;
UIGraphicsBeginImageContext(self.view.frame.size);
[drawImage.image drawInRect:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 5.0);
CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 1.0, 0.0, 0.0, 1.0);
CGContextBeginPath(UIGraphicsGetCurrentContext());
CGContextMoveToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), currentPoint.x, currentPoint.y);
CGContextStrokePath(UIGraphicsGetCurrentContext());
drawImage.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
lastPoint = currentPoint;
mouseMoved++;
if (mouseMoved == 10) {
mouseMoved = 0;
}
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
if ([touch tapCount] == 2) {
drawImage.image = nil;
return;
}
_startPoint = [touch locationInView:self.view];
if(!mouseSwiped) {
UIGraphicsBeginImageContext(self.view.frame.size);
[drawImage.image drawInRect:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 5.0);
CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 1.0, 0.0, 0.0, 1.0);
CGContextMoveToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
CGContextStrokePath(UIGraphicsGetCurrentContext());
CGContextFlush(UIGraphicsGetCurrentContext());
drawImage.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
}
}
答案 0 :(得分：-1)
-(void)digitalSignatureCalled{
//viewSign.backgroundColor = [UIColor lightGrayColor];
//create a frame for our signature capture based on whats remaining
imageFrame = CGRectMake(0, 50, 500, 450);
//allocate an image view and add to the main view
mySignatureImage = [[UIImageView alloc] initWithImage:nil];
mySignatureImage.frame = imageFrame;
mySignatureImage.backgroundColor = [UIColor whiteColor];
[viewSign addSubview:mySignatureImage];
}
//when one or more fingers touch down in a view or window
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
//did our finger moved yet?
fingerMoved = NO;
UITouch *touch = [touches anyObject];
//just clear the image if the user tapped twice on the screen
if ([touch tapCount] == 2) {
mySignatureImage.image = nil;
return;
}
//we need 3 points of contact to make our signature smooth using quadratic bezier curve
currentPoint = [touch locationInView:mySignatureImage];
lastContactPoint1 = [touch previousLocationInView:mySignatureImage];
lastContactPoint2 = [touch previousLocationInView:mySignatureImage];
}
//when one or more fingers associated with an event move within a view or window
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
//well its obvious that our finger moved on the screen
fingerMoved = YES;
UITouch *touch = [touches anyObject];
//save previous contact locations
lastContactPoint2 = lastContactPoint1;
lastContactPoint1 = [touch previousLocationInView:mySignatureImage];
//save current location
currentPoint = [touch locationInView:mySignatureImage];
//find mid points to be used for quadratic bezier curve
CGPoint midPoint1 = [self midPoint:lastContactPoint1 withPoint:lastContactPoint2];
CGPoint midPoint2 = [self midPoint:currentPoint withPoint:lastContactPoint1];
//create a bitmap-based graphics context and makes it the current context
UIGraphicsBeginImageContext(imageFrame.size);
//draw the entire image in the specified rectangle frame
[mySignatureImage.image drawInRect:CGRectMake(0, 0, imageFrame.size.width, imageFrame.size.height)];
//set line cap, width, stroke color and begin path
CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 3.0f);
CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 0.0, 0.0, 0.0, 1.0);
CGContextBeginPath(UIGraphicsGetCurrentContext());
//begin a new new subpath at this point
CGContextMoveToPoint(UIGraphicsGetCurrentContext(), midPoint1.x, midPoint1.y);
//create quadratic Bézier curve from the current point using a control point and an end point
CGContextAddQuadCurveToPoint(UIGraphicsGetCurrentContext(),
lastContactPoint1.x, lastContactPoint1.y, midPoint2.x, midPoint2.y);
//set the miter limit for the joins of connected lines in a graphics context
CGContextSetMiterLimit(UIGraphicsGetCurrentContext(), 2.0);
//paint a line along the current path
CGContextStrokePath(UIGraphicsGetCurrentContext());
//set the image based on the contents of the current bitmap-based graphics context
mySignatureImage.image = UIGraphicsGetImageFromCurrentImageContext();
//remove the current bitmap-based graphics context from the top of the stack
UIGraphicsEndImageContext();
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
//just clear the image if the user tapped twice on the screen
if ([touch tapCount] == 2) {
mySignatureImage.image = nil;
return;
}
//if the finger never moved draw a point
if(!fingerMoved) {
UIGraphicsBeginImageContext(imageFrame.size);
[mySignatureImage.image drawInRect:CGRectMake(0, 0, imageFrame.size.width, imageFrame.size.height)];
CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 3.0f);
CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 0.0, 0.0, 0.0, 1.0);
CGContextMoveToPoint(UIGraphicsGetCurrentContext(), currentPoint.x, currentPoint.y);
CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), currentPoint.x, currentPoint.y);
CGContextStrokePath(UIGraphicsGetCurrentContext());
CGContextFlush(UIGraphicsGetCurrentContext());
mySignatureImage.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
}
}
//calculate midpoint between two points
- (CGPoint) midPoint:(CGPoint )p0 withPoint: (CGPoint) p1 {
return (CGPoint) {
(p0.x + p1.x) / 2.0,
(p0.y + p1.y) / 2.0
};
}
-(void)clickToSave:(id)sender{
//convert image into .png format.
viewNewSign.image = mySignatureImage.image;
if (mySignatureImage.image == nil) {
imgString = @"NoSignature";
}else{
imgString = [self getStringFromImage:mySignatureImage.image];
}
NSLog(@"image saved = %@",imgString);
NSLog(@"image length = %lu",(unsigned long)imgString.length);
viewSign.hidden = TRUE;
scroll.scrollEnabled = YES;
[scroll bringSubviewToFront:viewSign];
}
-(NSString *)getStringFromImage:(UIImage *)image{
if(image){
NSData *dataObj = UIImagePNGRepresentation(image);
//[appDelegate showAlert:@"Data Size" message:[NSString stringWithFormat:@"Data length = %lu",(unsigned long)dataObj.length]];
return [dataObj base64EncodedStringWithOptions:0];
} else {
return @"";
}
}
-(void)clickToClear:(id)sender{
[self digitalSignatureCalled];
}
- (UIImage*)imageWithImage:(UIImage*)image
scaledToSize:(CGSize)newSize;
{
UIGraphicsBeginImageContext( newSize );
[image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}